I spoiled it a bit in the headline but in case you didn't read it, you should know that the Games with Gold free games for October were revealed today. The games include Chariot, Battlefield: Bad Company 2, and Darksiders 2.
Chariot, the newest ID@Xbox game from Canadian developers Frima, is a couch co-op platformer that can be played alone or with a friend. Players take the role of the brave Princess or her faithful Fiancé as they maneuver the departed king’s coffin-on-wheels through 25 levels set in five vibrant underground environments, with his majesty’s ghost giving them a piece of his mind every step of the way. Filled to the brim with emergent physics-based gameplay, Chariot offers hours of exciting exploration, fast-paced ride sequences and mountains upon mountains of loot!

Battlefield: Bad Company 2, brings the award-winning Battlefield gameplay to the forefront of Xbox 360 console with best-in-class vehicular combat and unexpected "Battlefield moments." Vehicles like the ATV and a transport helicopter allow for all-new multiplayer tactics on the Battlefield. You can compete in four-player teams in two squad-only game modes, fighting together to unlock exclusive awards and achievements. Battles are set across expansive maps, each with a different tactical focus. The game also sees the return of the B Company squad in a more mature single-player campaign.

Finally, Xbox 360 players get a chance to play one of the platform’s most underrated games: Darksiders II, which continues the series’ emphasis on huge environments, exploration, and a deep and rewarding story. Combine that with fantastic voice acting, impressive visuals, and a huge variety of procedurally generated loot (not to mention character-building options), and you’ll quickly find yourself enraptured by Darksiders II’s depth and top-notch game design. Did we mention you get to play as Death himself? Yeah.

To summarize:
Chariot - October 1-31 - Xbox One
Battlefield: Bad Company 2 - October 1-15 - Xbox 360
Darksiders 2 - October 16-31 - Xbox 360

(via Xbox)